Water-repellent nonfibrous cellulosic material and process of preparing same



V identified hereinabove.

I Q Patented July 1953 UNITED STATES ATENT. OFFICE YPA'RING SAME LO SICMATERIAL AND PROCESS OF -PRE- William M. Woodirig, Springdale, and TzengJ iueq Suen, Stamford, Conn, assignors to American Cyanamid Company, N

ration of Maine ew York, N. -Y.', a corpo- No Drawing. Continuation ofabandoned application Serial No. 160,386, May 5, 1950. This applicationJuly 1, 1952, Serial No. 296,708

' setting urea-formaldehyde resin modifiedb-y re- :action with acompound having the general formula: NH2(CH2)1LOSO3X wherein n is awhole number between 1 and 6 inclusive, and X is a member of thegroup'H, Li, Na, NHi, and hydrogen in combination with a water solubletertiary amine, for the purpose of improving the bonding .of saidcellulosic materials to subsequently appliedv water repellent topcoats.This invention further relates to a process of treating nonfibrousregenerated cellulosic materials with a water soluble modifiedurea-formaldehyde resin as defined hereinabove for the purpose ofimproving the water repellency of said cellulosi'c materials. Thisinvention further relates to Water repellent non-fibrous regeneratedcellulosic materials bonded to a waterrepellenttopcoat by use of a watersoluble modified urea-formaldehyde resin as defined hereinabove.

erated cellulosic material comprising a nonfibrous regeneratedcellulosic material bonded to a water repellent topcoat by means of awater soluble modified urea-formaldehyde resin as A.further object ofthe present invention is to produce a coated nonfibrous regeneratedc'ellulosi'c material which is so securely bonded to said coating thatit can withstand moist or wet conditions for prolonged periods of timewithout resulting in a separation of the cellulosi'c material from theWater repellent topcoat, A further object of the present invention is toimprove the water repellen'cy of coated cellulosic materials,particularly cellulosic films,

. 2 Y may then be withdrawn from the resin solution and treated with aplasticizing agent followed by a drying of the film, a partial curingofthe resin.

impregnated into the film surface and the subsequent application of awater repellent coating to said film surface. A further variation of thebasic process may be accomplished by incorporating the plasticizingagent into the aqueous resin solution whereby the impregnation and theplasticization of the" film can be accomplished in a one step process.In this modification, the film would be removed from the resinplasticizing bath, dried, the impregnated resin partially cured and thetopcoat bonded thereto. A still further modification of the basicprocess can be accomplished by spraying the resin solution on to thefilm, either in combination with or separately from the treatment withthe plasticizer. In either event. all other steps in the treatment ofthe film would be substantially the same.

The water soluble urea-formaldehyde resins modified by reaction with acompound having the general formula: NH2(CH2)01OSO3X, Wherein'n is awholenumber' between 1 and 6, inclusive,

.and X is a member of the group hydrogen, Li, Na, VNHI, and hydrogen incombination with a disclosed in the copending application of one of thepresent applicants, namely T. J. Suen. That application carries theSerial No. 125,152 and was filed November 2, 1949. Therein, a completedisclosure of the method of preparing these modified urea-formaldehyderesins is set forth in great to such an extent that the use of saidcellulosic materials can be extended considerably in their fields ofapplication, whereby the utility of said non-fibrous regeneratedcellulosic materials is greatly enhanced. These and other objects of thepresent invention will be discussed more fully hereinbelow.

In the practice of the process of the present invention, the treatmentofthe non-fibrous regenerated cellulosic materials can be accomplishedin a number of different Ways. For instance, one may immerse a wet,reswollen sheet of. cellophane (a non-fibrous. regenerated cellulosicmaterial) in an aqueous solution'of the modified urea-formaldehyde resinas defined hereinabove, whereby said film surface becomes impregnatedwith the resin solution. The film detail. In order that the presentinvention may be completely understood, however, the'followingdiscussion of these resins and method of preparation is set forth. I

In the preparation of the urea resins used in the practice of theprocess of the present invention, one may combine urea and formaldehydeunder alkaline conditions, as the first stage of the reaction,subsequently adding thereto an .amino alkyl sulfuric acid and heatingthe re action mixture at refiux temperatures, thereafter cooling themixture under acid conditions and maintaining the mixture atcomparatively low temperatures until the viscosity of a 45% solidssolutionof the reaction mixture in Water is at least B on theGardner-Holdt scale at 25 0/ and preferably within the range of F-Jonthat heated at elevated temperatures within the range of about 70-0 C.under alkaline conditions, preferably at a pH of about 8-9 for a periodof about l120 minutes. The reaction mixture may then be heated at refluxtemperatures for a period of about -300 minutes and'the pH of thereaction system at this temperature is not critical and need not becontrolled on either the alkaline or the acid side. The pH of thereaction mixture may then be adjusted to aboutl to 5 but preferably 2 to4 for a period of time suificient to permit the reaction mixture toreach a viscosity of at least B on the Gardner-l-Ioldt scale when theviscosity test is applied to a 45% solids solution of the resin in Waterat C. This viscosity increase may be'effected either by continuedheating or cooling but preferably by cooling to a temperature of about25-60 C. These and other modifications of the reaction process maybeaccomplished in the preparation of the resins per so. In order thatthe method of preparation of these resins which are used in the practiceof the process of the present invention be more completely understood,the following detailed examples are set forth for the purr RESIN A 60parts of urea (1 mol), 178 parts of a 37% aqueous solution offormaldehyde (2.2 mols) and 0.66 part of 10 sodium hydroxide solutionare introduced into a suitable reaction chamber to form a mixture with apH of 9.5. The mixture is heated to a temperature of 70-80 C. andmaintained at 70-80 C. 'for a minute period, thereupon 8.4 parts (0.05mol) of 2-aminoethylsulfuric acid dissolved in 13.8 parts of a 10%sodium hydroxide solution and 10 parts of water are introduced into thereaction system. The pH is then adjusted to about 2 with 10%hydrochloric acid and the reaction mixture is refluxed for 60 minutes.During the refluxing, the pH of the solution is adjusted to about 2.2 bythe addition of 10% sodium hydroxide. The reaction mixture is thencooled to a temperature of about 40 to C. and maintained at thattemperature until the viscosity at 25 C. of a 45% solids solution of thereaction mixture in water is between land J on the Gardner-Holdt scale.The resinous solution is then neutralized with 10% sodium hydroxide.

RESIN B parts of urea and 203 parts of a 37% aqueous solution offormaldehyde and 0.66 part of a 10% solution of sodium hydroxide areintroduced into a suitable reaction chamber and heated for a period ofabout 30 minutes at a temperature of about 70 to 80 C. The pH of thereaction mixture prior to the beginning of the exothermic re- 4 has aviscosity, at 25 C. of about H on the Gardner-Holdt scale. The resinoussolution may then be neutralized with 10% sodium hydroxide.

RESIN C heated to 7080 C. for a 30 minute period. 8.5

parts of 2-aminoethylsulfuric acid dissolved in 18.7 parts of 10% sodiumhydroxide solution and 10 parts of water are then introduced into thereaction mixture and the pH then is about 5.7. The reaction mixture isheated to reflux (about 96 C.) for a 60 minute period during which timethepI-I drops to about 2.5. The reaction mixture is then cooled to 45 C.and maintained at that temperature for about 25 minutes, whereupon thefinal viscosity, at 25 C., of a 45% solids solution of the resin inwater is about D on the Gardnerl-Ioldt scale. neutralized.

RESIN D 60 parts of urea, 162 parts of a 37% aqueous formaldehydesolution and 0.66 part of a 10% sodium hydroxide solution are introducedinto a suitable reaction chamber to form a mixture with a pH at 9.6. Themixture is heated to and maintained for 30 minutes at a temperature ofabout 70-80 C. 8.5 parts of 2-aminoethylsulfuri-c acid dissolved in 19.8parts of a 10% sodium hydroxide solution and 10 parts of water are thenintro duced into the system. The pH is adjusted to 5.9 and the mixtureis heated to reflux (97 C.) for a 60 minute period. The final pH isabout 2.6 and the mixture is cooled to a temperature of about 25 C. andmaintained at that temperature for about 18 minutes. The viscosity, at25 C., of a 45% resin solids solution'in water is about H on theGardner-Holdt scale. It is then neutralized with dilute sodiumhydroxide.

RESIN E of Z-arninoethylsulfuric acid dissolved in 9.4 parts action wasabout 9.4. Thereupon, 8.5 parts of of a 10% aqueous solution of sodiumhydroxide and 5 parts of Water are then introduced into the reactionsystem. The pH is about 5.6. The reaction mixture is then heated atreflux temperature (96 C.) for approximately 60 minutes. The pH drops toabout 2.5. The mixture is then cooled to a temperature at 40-45" C. andis maintained at that temperature for a period of about 11 minutes. Itis then neutralized. The final viscosity at 25 C. of a 45 solidssolution is about F-G on the Gardner-Holdt scale.

RESIN F 60 parts of urea and 178 parts of a 37 aqueous formaldehydesolution are introduced into a suitutes. A 45% solids solution of theresin in water able reaction chamber and the pH of the mix is adjustedto 9.6 by the addition of 0.66 part of a 10% sodium hydroxide solution.The mixture is then heatedfor a 30 minute period at a temperature ofto.80 C. 12.8 parts of 2-aminoethyl sulfuric acid (0.99 mol) dissolvedin 25.5 parts of The pH of the resin syrup is then Holdt scale.

parts of water are then introduced into the reaction mixture. The pH isabout 5.8. The mix ture is heated at reflux temperature (97 C.) forabout 60 minutes. The pH drops to about 2.5. While keeping the pI-I atthis level, the reaction mixture is cooled to and maintained at about 50C. for about 53 minutes. It is then neutralized. The final viscosity ofa 45% solids resin solution at 25 C. is about F on the Gardnerv RESIN G60 parts of urea and 178 parts of a 37 aqueous formaldehyde solution areintroduced into a suitable reaction vessel and the pH- of the mixture isadjusted to about 9.6 by the addition of 0.66 part of a 10% sodiumhydroxide solution. The mixture is then allowed to react at atemperature of about 70 to 80 C. for a 30 minute period. Thereupon, 17parts of 2-aminoethylsulfuric acid (0.12 mol) dissolved in 25 parts of a10% sodium hydroxide solution and 10 parts of water are introduced intothe reaction mixture. The pH is about 5.2. The mixture is heated atreflux temperature (95 C.)' for about 60 minutes. At the end ofrefluxing the pH of the mixture is 2.2. The mixture is then cooled to 50C. and maintained at that temperature for 43 minutes. It is thenneutralized with parts of a 10% sodium hydroxide solution. The finalviscosity of the resin is H on the Gardner-Holdt scale.

RESIN H 180 parts of urea (3 mols), 511 parts of a 37% aqueousformaldehyde solution (6.3 mols), 6 parts of triethanolamine, and asolution of 17 parts of 2-aminoethylsulfuric acid (0.12 mol) and 60parts of Water are mixed together in a suitable reaction chamber. The pHis measured at 8.3 (glass electrode). The solution is heated to refluxand maintained at that temperature for ap- RESIN I 240 parts of urea (4mols) is'dissolved in 648 parts of a 37% aqueous solution offormaldehyde (8 mols) and the pH is adjusted to 8.7 withtriethanolamine. The reaction mixture is heated to reflux temperatureand maintained at reflux for approximately 30 minutes. The reactionmixture is then cooled to 80 C. and a solution of 17 parts ofZ-aminoethylsulfuric acidin 38 parts 1 of a 10% caustic solution and 20parts of water is added. The pH is then adjusted to 6.3 with 18%hydrochloric acid. The reaction mixture is brought to reflux again andmaintained at that temperature for an additional 30 minutes. The pH isthen readjusted to 3.9 with an 18% hydrochloric acid solution and thereaction mixture is then refluxed for an additional 15 minutes. The pHof the reaction mixture is then adjusted to about 7.5 with a 10% causticsolution andcooled. The viscosity of the resin syrup containing 45%solids is about F on the Gardner-Holdt scale.

It will be noted from the aboveexamples that the process for thepreparation of' these resins 6 is preferably carried out in threestages, namely the first stage in which the urea and formaldehyde arepermitted to react under alkaline conditions by heating to a temperatureof about 70 to C. for a 30 minute period. Thereupon the amino alkylsulfuric acid, dissolved in dilute alkaline solutions, is added and themixture refluxed for about one hour. This second phase is, as a rule,continued under acid conditions and is generally referred to as the acidstage because the pH is controlled within the limits of about 1-5 andpreferably between 2 and 4. The third stage is the ageing or thickeningstage, which must be conducted under acid conditions and preferablywithin the pH range of 3 to 4. This third stage may be accomplished bycooling the reaction mixture at a temperature varying 'betweenabout 25and 60 C. for a sufficient period of time to give the desired viscosityto the resin solution. The time factor during this third stage is of noconsequence, but the important thing torememher is thatthe viscosity beobserved so closely that it is kept within the desired range.

The purpose in establishing 45% resin solids solution in water as thebasis for viscosity determinations is purely an arbitrary criterion. Any

other solids content could be used but it would necessitate applyingviscosity limits differing from those setforth. The viscositymeasurement as set forth on the established solids basis establishes acriterion whereby the degree of polymerization in the resin formationcan be ascertained. In the use of these resin solutions, it is customaryto use solids concentrations far below the 45% resin solids used as theviscosity criterion so that,-as a consequence, it is necessary to dilutethe resin solution to the desired range before application.

.It has been set forth hereinabove that the modifierfor theurea-formaldehyde resin should 1 be an aminoalkylsulfuric acid orderivative thereof having the formula: NH2( CH2) nOSOBX, wherein theletter n signifies a whole number between 1 and '6, inclusive, and Xdesignates a radical selected from the group consisting of H, Na, K, Li,NH4 and hydrogen in combination with'a water soluble amino group, suchas those derived from triethylamine, trimethylamine, triethanolamine,and the like. Amongst that group are such compounds asaminomethylsulfuric acid, 2- aminoethylsulfuric acid,3-aminopropylsulfuric acid, 4-aminobutylsulfuric acid,5-aminoamylsulfuric acid, and fi-aminohexylsulfuric acid and the saltsthereof as indicated above. It is preferred that the amino group and thesulfuric acid or salt group be attached to the two end carbon atoms ofthe alkyl group. The proportions of aminoallrylsulfuric acid which maybe used in the practice of the process of this invention may be variedwithin the limits of 0.0l5-0.25 mol of aminoalkylsulfuric acid per molof urea.

The molar proportions of formaldehyde to urea in the preparation of theresins of the instant invention may be varied within the limits of 1.5:1to 3:1 respectively, but it is preferred that those resins which havemol ratios of 1.821 and 2.5 1 be used respectively.

If it is desired to introduce the three reacting components initiallyinto the reaction chamber in the ran'ge'of proportions set forthhereinabove, one may adjust the pH of the mixture to the alkaline sideand preferably within the range of 8-9. The mixture may be heated for aperiod of froml5 to 120 minutes at a temperature varying between 70 C.and C. The subsequent heating at reflux temperatures may be accomplishedin a period of 15 to 300 minutes. The pH of the reaction mixture, duringthis phase of reaction, is not critical and may be on either the acid oralkaline side. In the ageing or thickening stage, however, the pH mustbe controlled within the range of 1 to 5, with the range of 2 to 4producing optimum results. The reaction mixture may be cooled to atemperature within the range of 25-60 C. and held within that rangeuntil the desired viscosity is reached.

The cellulosic films to be treated in accordance with the practice ofthe process of the present invention may be regenerated celluloseprepared from solutions of cellulose xanthate, cuproammonium cellulose,cellulose acetate, cellulose nitrate, and the like. The cellulosic filmsmay also be of a cellulose ester or other such as cellulose acetate,cellulose nitrate, ethyl cellulose, methyl cellulose or similarcellulosic material. The treated cellulosic body may be freshly preparedand still wet and in a swollen condition or it may have been previouslyprepared, dried, and stored but in the latter event, it may be immersedin water so as to render it wet and swollen prior to treatment, or thecellulosic body may be rendered wet and swollen by the simultaneousimmersion in the aqueous resin dispersion while the impregnating step isbeing accomplished.

The coating compositions which may be bonded to the cellulosic film basemay be any of the conventional coating compositions such as thosecontaining, as the film forming constituents, compounds such ascellulose acetate, cellulose nitrate, ethyl cellulose, methyl cellulose,deacetylated chitin, rubber, chlorinated rubber, rubber hydrochloride,cyclocized rubber, synthetic rubbers of various types, methacrylatepolymers and other conventional film forming materials. In order toenhance the water repellent effects of the topcoat material, one may usewaxes such as paraffin wax, scale wax, beeswax, montan, carnauba,candelilea wax, which are incorporated into the coating compositionsprior to application on the treated cellulosic film. Plasticizers, gums,pigments and the like, may also be added to the coating composition whenand as desired.

In the practice of the process of the present invention, it is desiredto incorporate a plasticizing agent into the film as one of the steps inthe preparation of the final product. This step of introducing theplasticizing agent into the film may be accomplished prior to the resinimpregnation step, simultaneously therewith or subsequent thereto. As astill further modification, it is possible to impregnate the film withthe resin, dry the film and then introduce the plasticizing agent intothe film prior to the step of the partial polymerization of the resin onthe film and the final step of coating with the water repellent coatingcomposition. Any of the conventional plasticizing agents may be used butit is generally preferred that one use glycerol in about an 8% aqueoussolution as this plasticizing agent appears to be the best suited fromthe standpoint of efiectiveness and economy.

In order to illustrate more completely, the process of the presentinvention, the following examples are set forth solely for the purposeof illustration and any recital of specificv details should not beinterpreted as limitations on the case except as indicated in theappended claims.

Example 1 A strip of wet, swollen regenerated cellulose is immersed inan aqueous solution of the ureaformaldehyde 2-aminoethylsulfuric acidresin, such as that prepared according to Resin A set forth hereinabove,containing 1% by weight of resin based on the total weight of thesolution. The film is then removed from the resin solution andintroduced into the plasticizing bath containing 8% glycerol in aqueoussolution, removed therefrom, dried for 10 minutes at 200 F. and coatedwith a water repellent lacquer.

Example 2 The process according to Example 1 is repeated except that theplasticizing agent is incorporated into the resin dispersion and thecellulosic film is introduced therein and after removal therefrom isdried and the resin impregnated onto the surface of said film, ispartially polymerized by heating for approximately 10 minutes at 200 F.The treated film is then coated with a water repellent lacquer.

Example 3 The process according to Example 1 is repeated except that thestep of immersing the film in the plasticizing bath is accomplishedprior to the immersion in the resin dispersion so that the film uponremoval from the resin solution is dried for about 10 minutes atapproximately 200 F. and coated with a water repellent lacquer.

In order to test the effectiveness of the bonding of the topcoat to thfilm base, a sloughing test was conducted in which the films wereimmersed in water at a temperature of about l-l90 F. These tests arecontinued until the water repellent topcoat shows signs of separatingfrom the cellulosic film base. A film prepared according to Example 1was allowed three days of natural ageing after preparation but prior tothe test, the film prepared according to Example 3 was allowed a naturalageing time of ten days after preparation but prior to the hot sloughtest and a film prepared according to Example 3 was allowed to age forfifteen days before the test. The following chart is set forth for thepurpose of showing the relative values of the bonding efliciency of theresins as contrasted with a blank specimen which had been treated in allrespects in the same manner as Examples 1, 2 and 3 except that no resinanchoring agent was used on these blanks.

CHART I lfglot SloIugh ests tal Concentrni m z Oven Curing TreatedCellulosic tion of Time F.) Film Produced by Resin in D in minutesSolution 33 .after unng Percent 1 1 8 l6 0 1 1 5 2 (l) 2 3;) 42 59 1Example 3 1 10 39 53 68 Blank C 0 14 1.5 1.5 Example 3 1 15 54 In thepractice of the process of the present invention, it is not necessary tohave very substantial amounts of the resin present in the solution. Onemay use as little as 0.01% and up to about 10% of resin by weight basedon the total weight of the. aqueous solution. It is preferred, however,to use between about 0.1% and 3% by weight of resin based on the totalweight of th resin solution.

There; ar many advantages in the use of the resins of the presentinvention such as the light color as these resins are either-virtuallycolorless or extremely light. colored. A further advantage of thepresent process resides in thefact that the cellulosic films may betreated by these resins in either a neutral or slightly alkalinesolution which is to be highly desired over the use of the resinoussolutions which must be acidic. When resins are used that require acidpI-Is, it is almost invariably necessary to make use of a wash ing stepin orderto remove excess acid, which in turn avoids degradation of thecellulose. This washing step tends to reduce the efficiency of thebonding characteristic of the acid type resins and increases the cost ofoperation. A further advantage which the present process provides is themuch higher bond strength'which is accomplished by the use of theseparticular resins. Furthermore, these resins cure easily, therebyproducing maximum bond strength with low temperature cures or shortperiods of natural ageing.

The following chart is set forth for the purpose of showing the bondingeificiency of these resins when lower concentrations of resin in aqueoussolution are used. These films were prepared in a manner comparabl tothat set forth in Example 1'. except that the resin solution containedonly 0.1% by weight based on total solution Weight of resin. r

, V 10 tially-polymerizing said resin and applying a wa terrepellentcoating thereto.

3. A process for treating non-fibrous regenerated cellulosic filmcomprising the steps of impregnating the surface of said film with awater soluble urea-formaldehyde resin modified by reaction with acompound having the general formula: NH2(CH2)nOSO3X, wherein n is awhole number between 1 and 6, inclusive, and X is a member of the groupconsisting of fH, Li, Na, N354, K and hydrogen in combination with awater soluble tertiary amine, wherein the mol ratios of urea,formaldehyde and aforementioned compound are-within the range of121.520.015. and 1:3.0:0.25, respectively, wherein said resin is inaqueous solution and contains 0.01 %-10% by weight of resin based. onthe total weight ofisolumember of the group. consistingofH, Li, Na,

CHART II Hot Slough Test Treated cellulosic Concentra- Natural TotalOven Cur- Film Produced in tion of Re- AgeingTime ing Time (190 F.)

accordance with sin in S01 in Days af- Example 1 ution ter Curing 3 min.8 min.

Percent mula: NH2(CH2)11OSO3X, wherein n is a wholenum'ber between 1 and6, inclusive, and X is a member of the group consisting of H. Li, Na, NH4, K and hydrogen in combination with a water soluble tertiary amine,wherein the mol ratios of urea, formaldehyde and aforementioned compoundare within the range 1:.1.5:0.015 and -1:3.0:0.25, respectively,introducing apla-sticizing agent into the film, drying the film, therebypartially polymerizing said resin and applying a water repellent coatingthereto.

2. A process for treating non-fibrous regenerated cellulosic filmscomprising the steps of impregnating the surface of said films with awater soluble urea-formaldehyde resin modified by reaction with acompound having the general formula: l lH2(CH2)n0SO3X wherein n is awhole number between 1 and 6,- inclusive, and X is a member of thegroups consisting of H, Li, Na, NH4, K and hydrogen in combination witha water soluble tertiary amine, wherein the mol ratiosof urea,formaldehyde and aforementioned com .pound are within the range1:1.8:0.03 and 112.550.12, respectively, introducing a plasticizingagent into the film, drying the film, thereby par- NH4, K and hydrogenin combination with. a water soluble tertiary amine, wherein the molratios of urea, formaldehyde and aforementioned compound are within therange 1:1.8:0.03 and 112.520.12; respectively, introducing a.plasticizing agent into the film, drying the film, thereby partiallypolymerizing said resin and applying a water repellent coating theretowherein said resin is in an aqueous weight of solution.

5. A non-fibrous cellulosic film impregnated with a urea-formaldehyderesin modified by reaction with a compound of the general formula:NH2(CH2),1LOSO3X, wherein n is an integer between 1 and 6, inclusive,and X is a member of the group consisting of H, Li, Na, NH4, K andhydrogen in combination with a water soluble tertiary amine, and a waterrepellent topcoat bonded thereto, and *wherein the mol ratios of urea,formaldehyde and aforementioned compound are within the range1:1.550.015 and l:3.0:0.25, respectively.

6. A process for treating non-fibrous regenerated cellulosic filmscomprising the steps of impregnating the surface of said films with awater soluble urea-formaldehyde resin modified by reaction with acompound having the general '7. A process for treating non-fibrousregenerated cellulosic films comprising the steps of impregnatingthesurface of said films with a water soluble urea-formaldehyde resinmodified by reaction with a compound having the general formula;NI-Iz(CHz)nOSO3Na, wherein n is a whole number between 1 and(Linolusive, wherein the mol ratios of urea, formaldehyde andaforementioned compound are within the range solution containing 0.1%-3%by weight of resin based on the total 11 Y 1:1.8:0.03 and1:2.5:0.12,respectively, introducing a plasticizing agent into the film,drying the film, thereby partially polymerizing said resin and applyinga water repellent coating thereto.

8. A process for treating non-fibrous regenerated cellulosic filmcomprising the steps of impregnating the surface of said film with awater soluble urea-formaldehyde resin modified by reaction with acompound having the general formula: NHZ(CH2)12OSO3N&, wherein n is awhole number between 1 and 6, inclusive, wherein the mol ratios of urea,formaldehyde and aforementioned compound are within the range of1:1.5:0.015 and l:3.0:0.25, respectively, wherein said resin is inaqueous solution and contains 0.01 %-10% by Weight of resin based on thetotal weight of solution; introducing a plasticizing agent into thefilm, drying the film, thereby partially polymerizing said resin, andapplying a water repellent coating thereto.

9. A process for treating non-fibrous regenerated cellulosic filmcomprising the steps of impregnating the surface of said film with aWater soluble urea-formaldehyde resin modified by reaction with acompound having the general formula: NI-MCHzMOSOaNa, wherein n is awhole number between 1 and 6, inclusive, and wherein the mol ratios ofurea, formaldehyde and aforementioned compound are within the range1:1.8:0.03 and 1:2.5:0.12, respectively, introducing a plasticizingagent into the film, drying the film, thereby partially polymerizingsaid resin and applying a Water repellent coating thereto wherein saidresin is in an aqueous solution containing 0.1 %-3% by weight of resinbased on the total Weight of solution.

10. A non-fibrous cellulosic film impregnated with a urea-formaldehyderesin modified by reaction with a compound of the general formula:NH2(CH2)1LOSO3Na, wherein n is an integer between 1 and 6, inclusive,and a Water repellent topcoat bonded thereto, and wherein the mol ratiosof urea, formaldehyde and aforementioned compound are within the range1:1.5:0.015 and l :3.0 0.25, respectively.

Name Date DAlelio Nov. 11, 1945 Number OTHER REFERENCES Rollins, Journalof the American Chemical Society, vol. 60, pages 2312-14.

1. A PROCESS FOR TREATING NON-FIBROUS REGENERATED CELLULOSIC FILMSCOMPRISING THE STEPS IMPREGNATING THE SURFACE OF SAID FILMS WITH A WATERSOLUBLE UREA-FORMALDEHYDE RESIN MODIFIED BY REACTION WITH A COMPOUNDHAVING THE GENERAL FORMULA: NH2(CH2)NOSO3X, WHEREIN N IS A WHOLE NUMBERBETWEEN 1 AND 6, INCLUSIVE, AND X IS A MEMBER OF THE GROUP CONSISTING OFH. LI, NA, NH4,K AND HYDROGEN IN COMBINATION WITH A WATER SOLUBLETERTIARY AMINE, WHEREIN THE MOL RATIOS OF UREA, FORMALDEHYDE ANDAFOREMENTIONED COMPOUND ARE WITHIN THE RANGE 1:1.50.015 AND 1:3.0:0925,RESPECTIVELY, INTRODUCING A PLASTICIZING AGENT INTO THE FILM, DRYING THEFILM, THEREBY PARTIALLY POLYMERIZING SAID RESIN AND APPLYING A WATERREPELLENT COATING THERETO.